Neutron Powder Diffractometer
POWDER | HB-2A | HFIR
Instrument Overview: The papers "The high-resolution powder diffractometer at the high flux isotope reactor" and "Powder Suite" have the HB-2A (POWDER) instrument capabilities and specifications.
User Guides for an experiment at HB-2A
Preparing for your experiment
Choose your sample holder:
1) Standard and Tip-Top powder cans with dimensions.
Check the sample absorption to choose the most suitable powder can dimensions: NCNR Neutron Attenuation and Activation Calculator
Loading the powder into the sample holder:
Using the on-site sample can sealer
Instrument training for HFIR users
Running the experiment:
Reference guide for doing measurements at HB-2a
Live experiment viewing:
Live instrument display
HB2A monintor shows all completed runs
Looking at the data:
All data is autoreduced and can be accessed through ONCat or the analysis cluster
Further details can be found in this guide: Accessing autoreduced data and combining data
Analyzing the data:
Basic analysis: Rietveld Refinement of HB-2A Data Using FullProf Software
Detailed Lecture Notes and Step-By-Step examples with data for Magnetic Strucutre Refinements can be found on the following workshop websites:
Magnetic structure determination examples (2022)
Lecture notes and examples from 2019 workshop
Lecture Notes (2016 workshop)
Shipping Samples: Full instructions can be found on ORNL User Facilities Sample Handling and Shipping.
Sample Environment Capabilities: A list of equipment available at HB-2A can be found in the Sample Environment Equipment Database, this includes specifications and drawings. Ranges of current sample environment conditions are 30mK–1700 K, 0-6 Tesla, 0-2GPa (BeCu clamp cell) and 0-3kbar (Al-helium gas pressure cell). NOTE: All conditions are not attainable simultaneously, contact the instrument team for details.
Software Downloads for data analysis
- FullProf and GSAS-II are Rietveld refinement packages for determination of nuclear and magnetic structures.
- SaraH or newer website version – contains the user friendly magnetic structure analysis programs SARAh-Representational Analysis and SARAh-Refine. SARAh uses representational analysis to calculate 'symmetry allowed magnetic structures' that can then be directly utilized in Fullprof or GSAS.
- Bilbao Crystallographic Server - contains magnetic symmetry information, tutorials and examples.
- ISOTROPY - contains magnetic symmetry information, tutorials and examples.
Calibration Standards
Calibration for all wavelengths (Ge113 [2.41 A], Ge115 [1.54 A], and Ge117 [1.12 A]) and pre-sample collimator settings (IN = op_21_12, OUT = op_op_12):
| Cycle | Run dates | Calibration | Fullprof IRF | GSAS-II INSTPRM |
|---|---|---|---|---|
| 510 | 10/15/24 - 11/09/24 | Si + LaB6 | cycle510_FP.zip | cycle510_GSASII.zip |
| 509 | 09/03/24 - 09/28/24 | Si + LaB6 | cycle509_FP.zip | cycle509_GSASII.zip |
| 508 | 07/23/24 - 08/16/24 | Si + LaB6 | cycle508_FP.zip | cycle508_GSASII.zip |
| 507 | 06/11/24 - 07/05/24 | Si | cycle507_FP.zip | cycle507_GSASII.zip |
| 506 | 04/09/24 - 05/03/24 | Si + LaB6 | cycle506_FP.zip | cycle506_GSASII.zip |
| 505 | 02/27/24 - 03/22/24 | Si + LaB6 | cycle505_FP.zip | cycle505_GSASII.zip |
| 504 | 01/18/24 - 02/12/24 | Si + LaB6 | cycle504_FP.zip | cycle504_GSASII.zip |
| 503 | 08/29/23 - 08/11/23 | Si | cycle503_FP.zip | cycle503_GSASII.zip |
| 502 | 07/18/23 - 08/11/23 | Si | cycle502_FP.zip | cycle502_GSASII.zip |
| 501 | 05/23/23 - 06/16/23 | Si | cycle501_FP.zip | cycle501_GSASII.zip |
Example PCR file for Fullprof - Si Standard, cycle 507
Flourinert and Methanol-Ethanol
Calculation of Sample Absorption Correction: (mu) * (R)
Obtain mu [cm-1] using NCNR Neutron Attenuation and Activation Calculator
R is radius of powder can used for measurement, see List of available powder sample holders for sample can dimensions.
Acknowledgement Statement for User Publications
Intent to Publish: As a condition for performing nonproprietary research, the US Department of Energy requires users to publish results from their research. Authorship of publications based on research from these facilities should reflect the normal considerations of recognizing collaborations. It is also important to take into account the considerable efforts of the instrument scientists in their role of designing, constructing, and/or operating the instrument and related facilities. Results are typically published in peer-reviewed journals, proceedings, or presentations at technical conferences. Proprietary users are not required to publish.
Credit Line: All publications based on work done in whole, or in part, at the Spallation Neutron Source or the High Flux Isotope Reactor at Oak Ridge National Laboratory should acknowledge the facility (or facilities) with this required statement:
This research [or, A portion of this research] used resources at the High Flux Isotope Reactor [and/or Spallation Neutron Source, as appropriate], a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.
In addition, users are asked to credit the instrument(s) used in the body of the paper.
Contribute to Our Publication Records: After your results have been published submit the papers citation information via the Publications Portal.
Old and miscellaneous information not typically used anymore:
Old style powder cans: Sample preparation using powder cans
Graffiti – Old unsupported program that allowed the user to download HFIR data to their own computer and browse through the scans in the experiment.
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